我想找到我当前位置的地图并在我通过在 OSMdroid 中显示图标移动时对其进行更新。在给出特定位置的纬度和经度以及绘图图标时我发现没有问题,但是当我给出当前位置的纬度和经度时有两个错误。
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
mResourceProxy = new DefaultResourceProxyImpl(getApplicationContext());
setContentView(R.layout.main);
mMapView = (MapView) this.findViewById(R.id.mapview);
mMapView.setTileSource(TileSourceFactory.MAPNIK);
mMapView.setBuiltInZoomControls(true);
mMapView.setMultiTouchControls(true);
mapController = this.mMapView.getController();
mapController.setZoom(15);
Criteria criteria = new Criteria();
criteria.setAccuracy(Criteria.ACCURACY_FINE);
criteria.setAltitudeRequired(false);
criteria.setBearingRequired(false);
criteria.setCostAllowed(true);
criteria.setPowerRequirement(Criteria.POWER_LOW);
String provider = mLocMgr.getBestProvider(criteria, true);
Location location = mLocMgr.getLastKnownLocation(provider);
GeoPoint mypoint = new GeoPoint(location.getLatitude(), location.getLongitude()); // centre map here
GeoPoint mypointicon = new GeoPoint(location.getLatitude()+1000, location.getLongitude()+1000); // icon goes here
mapController.setCenter(mypoint);
mLocMgr = (LocationManager) getSystemService(LOCATION_SERVICE);
mLocMgr.requestLocationUpdates(LocationManager.GPS_PROVIDER, 1000, 100,
this);
ArrayList<OverlayItem> items=new ArrayList<OverlayItem>();
items.add(new OverlayItem("Here", "Sample Description", mypointicon));
this.mMyLocationOverlay = new ItemizedIconOverlay<OverlayItem>(items,
new ItemizedIconOverlay.OnItemGestureListener<OverlayItem>() {
@Override
public boolean onItemSingleTapUp(final int index,
final OverlayItem item) {
Toast.makeText(
MapOverLayGiveActivity.this,
"Item '" + item.mTitle, Toast.LENGTH_LONG).show();
return true; // We 'handled' this event.
}
@Override
public boolean onItemLongPress(final int index,
final OverlayItem item) {
Toast.makeText(
MapOverLayGiveActivity.this,
"Item '" + item.mTitle ,Toast.LENGTH_LONG).show();
return false;
}
}, mResourceProxy);
this.mMapView.getOverlays().add(this.mMyLocationOverlay);
mMapView.invalidate();
}
错误:java.lang.NullPointerException
java.lang.RunTimeException
我的代码有什么问题,我该怎么做?谢谢...